CollectionView.EmptyView not respecting layout.

[aksik]

Description

the simplest collection view:

`

<CollectionView.EmptyView>
    <ContentView>
        <StackLayout HorizontalOptions="Center" VerticalOptions="Center">
            <Label
                Margin="10,25,10,10"
                FontAttributes="Bold"
                FontSize="18"
                HorizontalOptions="Fill"
                HorizontalTextAlignment="Center"
                Text="No results matched your filter." />
            <Label
                FontAttributes="Italic"
                FontSize="12"
                HorizontalOptions="Fill"
                HorizontalTextAlignment="Center"
                Text="Try a broader filter?" />
        </StackLayout>
    </ContentView>
</CollectionView.EmptyView>

`

before update to 9.0.30 looked like (9.0.22):

after upgrading:

Steps to Reproduce

1. create maui template app and replace MainPage content with the one mentioned above.
2. update Microsoft.Maui.Controls 9.0.30

Link to public reproduction project repository

No response

Version with bug

9.0.30 SR3

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

9.0.22 SR2.2

Affected platforms

Android

Affected platform versions

Tested on Android 14

Did you find any workaround?

no workaround found

Relevant log output

[MitchBomcanhao]

maybe related CollectionView's EmptyView Does Not Fill Vertical Space ?
workaround on #18626 (comment) seems to work

[Zhanglirong-Winnie]

This issue has been verified Visual Studio 17.13 Preview 2.1 (9.0.30). Can repro this issue on Android platform. And on 9.0.22 works fine.

[rmarinho]

Is this a regression or a bug that was fixed? I guess the EmptyView is not taking the full height anymore. but instead sizing itself.

[aksik]

Is this a regression or a bug that was fixed? I guess the EmptyView is not taking the full height anymore. but instead sizing itself.

It is a regression. It's not about taking full height but positioning itself inside CollectionView (VerticalOptions="Center"). It's a very simple example but in more complex sceanarios (like inside RefreshView) it doesn't render at all. That's how we've noticed it - empty views disappeared in all our applications after upgading to .30. So yes, It's a clear regression.

[rmarinho]

So the screenshots are wrong @aksik ? Because on the screenshots above the only difference I manage to see is one taking full height and other does not . I don t see any view missing.

[aksik]

maybe related CollectionView's EmptyView Does Not Fill Vertical Space ? workaround on #18626 (comment) seems to work

Yes, I can confirm that this workaround works. However, as we have a lot of apps with a lot of empty views, changing all of them sounds ridiculous just tu update to latest version :/

[aksik]

So the screenshots are wrong @aksik ? Because on the screenshots above the only difference I manage to see is one taking full height and other does not . I don t see any view missing.

no, screenshots are ok, it's just the most basic example prepared to highlight the bug. The second screenshot shows empty view on top while still having VerticalOptions="Center". Looks like it's not aware of the height of collectionview it's inside of.

[RobTF]

Just been hit with this on our bugtracker from beta testers after updating MAUI to the latest version in our .NET 9 branch. It's these kind of obvious, silly regressions with MAUI which is the root of a lot of the framework complaints.